> "For several years I was sleeping with both her and another woman" generally implies that the wife left him
No it doesn't.
"For several years, I was sleeping with both her and another woman, she eventually had enough and filed for divorce" means that the wife left.
"For several years, I was sleeping with both her and another woman, she eventually had enough so she asked me to choose between her and the other woman. I chose to leave her for the other woman" means that the husband left. He could have chosen to stay with the wife, but chose not to.
This isn't a coherent viewpoint. How do you distinguish these two cases?
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1(A). Wife discovers cheating.
1(B). Wife gives ultimatum.
1(C). Husband declines ultimatum.
1(D). Husband leaves.
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2(A). Wife discovers cheating.
2(B). Wife gives ultimatum.
2(C). Husband declines ultimatum.
2(D). Wife leaves.
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You seem to be arguing that it's always scenario 1, because in step (C), the husband "could have chosen to stay with the wife, but chose not to". But that immediately implies that this scenario cannot occur:
3(A). Wife discovers cheating.
3(B). Wife gives ultimatum.
3(C). Husband declines ultimatum.
3(D). Wife stays.
What we know is that the husband sees no reason for the marriage to change, and the wife does. The breakup of the marriage, in this context, is almost always the wife's choice, as identified by the very simple criterion that it's something the wife wants and the husband doesn't want. She can equally choose to take the husband's offer of a stable marriage with adultery.
No it doesn't.
"For several years, I was sleeping with both her and another woman, she eventually had enough and filed for divorce" means that the wife left.
"For several years, I was sleeping with both her and another woman, she eventually had enough so she asked me to choose between her and the other woman. I chose to leave her for the other woman" means that the husband left. He could have chosen to stay with the wife, but chose not to.